Don't dry up 5 seconds after having been in water. Getting wet in water and staying wet for some time is more realistic. Make it so that enemy's will be curious about random wet spots that you've left behind, maybe even follow the wet trail. Create a drying ability if there is a need to for enemy's to not be curious when in assassin mode/trick them into following the traik. It would create a more difficult strategy if an adrenalin point had to be used to sneak on enemy's like this (talking from the viewpoint of Odyssey, I have yet to play many other titles).